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R E Jeacocke

Publications and source records attributed to R E Jeacocke.

4 recordsLinked to original sources
PubMed1991

The application of scanning confocal microscopy in cartilage research.

Scanning confocal microscopy has been used in conjunction with immunofluorescent localization to address two areas of debate in cartilage research. With the enhanced resolution and optical sectioning capability of this new technique, we have demonstrated that type IX collagen is preferentially located in an area around the chondrocyte, even in young cartilage. We have also shown that cathepsin B production is not confined to de-differentiated chondrocytes. The advantages and versatility of scanning confocal microscopy have thus clearly been demonstrated.

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PubMed1982

Calcium efflux during the cold-induced contraction of mammalian striated muscle fibres.

The efflux of 45Ca from mammalian slow twitch muscle fibres has been studied to provide a measure of the concentration of free Ca2+ in the sarcoplasm. The kinetically complex early phases of washout of the isotope are succeeded by a prolonged slower phase which exhibits first-order kinetics. This later phase is accelerated by caffeine, by preventing oxidative phosphorylation and also during an isometric contraction, whether this contraction is produced by lowering the temperature or by electrical stimulation. The local anaesthetic tetracaine abolishes the contraction caused by cold and in this case the rate constant for efflux is progressively lowered as the temperature is reduced (Q10 value of 2.3). The removal of external Na+ and Ca2+ reduces the efflux rate constant. Caffeine, sodium removal and the inhibition of oxidative phosphorylation, all potentiate the cold contraction and the associated extra 45Ca efflux. Ca removal causes the cold contraction to become phasic. It appears that caffeine, sodium removal, the inhibition of oxidative phosphorylation and a decrease in temperature to below 10 degrees C are all treatments which, like electrical stimulation, increase the sarcoplasmic free calcium concentration to varying degrees.

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